The hit series "Star Trek" celebrates the 50th anniversary of its television debut today (Sept. 8). Castmembers, astronauts and space agencies around the world have used social media to commemorate the series, tweeting photos and videos along with their congratulations. Here are some of their best tweets of the day.

The original "Star Trek" series only ran for three years (1966-1969). But thanks to the support of its massive fan base, the franchise is sure to live long and prosper.